System and method for assessing fluid distribution in a urine detection network

ABSTRACT

A system and method for assessing fluid distribution. According to one aspect of the disclosure, a fluid detection network is used to assess the fluid distribution of a fluid collection article having a plurality of tested regions. Each tested region of the fluid collection article is serviced by the fluid detection network. The fluid detection network is configured to indicate a fluid distribution of the fluid collection article. According to another aspect of the disclosure, a monitoring subsystem assesses a fluid distribution of a test area serviced by a fluid detection network, wherein the fluid detection network has a net characteristic indicative of the fluid distribution of the test area.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/253,807, filed Sep. 23, 2002 now U.S. Pat. No. 6,916,968,which claims the benefit of U.S. Provisional Patent Application No.60/324,278, filed Sep. 25, 2001; 60/344,795, filed Jan. 7, 2002;60/348,381, filed Jan. 16, 2002; 60/354,530, filed Feb. 8, 2002;60/357,624, filed Feb. 20, 2002; and 60/373,637, filed Apr. 19, 2002.This application also claims the benefit of U.S. Provisional PatentApplication Nos. 60/429,154, filed Nov. 25, 2002; 60/452,703 filed Mar.6, 2003; 60/454,390, filed Mar. 12, 2003; 60/467,272, filed May 2, 2003;60/473,001, filed May 22, 2003; 60/473,790, filed May 27, 2003; and60/494,031 filed Aug. 8, 2003. The content of the above referencedapplications is herein incorporated by reference for all purposes.

BACKGROUND

In the past, detecting the presence of urine, for instance in a diaperor bedding, has been accomplished by physically touching the potentiallywetted area. For convenience, speed, sanitation, and similar reasons,this method is less than ideal, particularly in a managed careenvironment. In such environments, urine detection is an ongoingprocess. Several patients may need to be repeatedly tested, which can bea time consuming, physically demanding, undesirable task. Often times,patients are in beds, covered with blankets, and testing for urine insuch circumstances is difficult using conventional methods. Somedetection methods utilize visual indicators, but these methods requireremoval of clothing and/or blankets, and cannot be discretely used by anadult wearing a diaper in public.

To maximize the utility of urine collection articles, such as diapers,such articles must be changed when they have collected the proper amountof urine. A person suffering from lack of bladder control maycontinuously leak urine, and the mere presence of urine in the articledoes not always necessitate a change. Changing a urine collectiongarment too soon can be wasteful because the maximum effectiveness ofthe garment is not utilized. Changing a garment too late may cause thewearer discomfort and/or irritation, and may also allow urine to spreadoutside of the garment. Therefore, to maximize the effectiveness of suchgarments, it is desirable to be able to determine the relative amount ofurine that has been collected by such a garment so that the garment maybe changed at the proper time. Industry experts estimate that absorbentarticles are used to only about 30% of their capacity, which results inunnecessary expenditure by consumers and undesirable environment impact.

The distribution of urine within an absorbent article may be at leastpartially dependent on the pattern of use. With a diaper, for example,the body position of the person using the article (i.e. lying on back,lying on front, lying on left side, lying on right side, etc.) willinfluence the fluid distribution within the diaper. Gravity may causeretained fluid to collect at a portion of the article that is relativelylow compared to other portions of the absorbent article. Because morefluid may be retained at the low side of the article, maximum capacitymay be reached at that area or a leak may occur there before other areasof the article retain any fluid.

SUMMARY

A system and method for assessing fluid distribution is provided.According to one aspect of the disclosure, a fluid detection network isused to assess the fluid distribution of a fluid collection articlehaving a plurality of tested regions. Each tested region of the fluidcollection article is serviced by the fluid detection network. The fluiddetection network is configured to indicate a fluid distribution of thefluid collection article. According to another aspect of the disclosure,a monitoring subsystem assesses a fluid distribution of a test areaserviced by a fluid detection network, wherein the fluid detectionnetwork has a net characteristic indicative of the fluid distribution ofthe test area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a fluid detection system.

FIG. 2 is a schematic view of a urine detection network.

FIG. 3 is a schematic view of a diaper serviced by a urine detectionnetwork.

FIG. 4 is a schematic view of a detector as used in a fluid detectionnetwork.

FIG. 5 is a somewhat schematic view of an embodiment of a urinedetection network.

FIG. 6 is a somewhat schematic view of an embodiment of an interfacemodule of a urine detection network.

FIG. 7 is a schematic view of an embodiment of a urine detectionnetwork.

FIG. 8 is a schematic view of another embodiment of a urine detectionnetwork.

FIG. 9 is a schematic cross section view of an embodiment of a urinedetection network.

FIG. 10 is a schematic cross section view of another embodiment of aurine detection network.

FIGS. 11–13 are schematic views of urine detection networks constructedfrom a single conductive element.

FIGS. 14–17 show a method of constructing portions of a fluid detectionnetwork from sheet material.

FIG. 18 is a schematic view of a urine detection network that includes adata storage mechanism.

FIG. 19 is a schematic view of a monitoring subsystem.

FIG. 20 is a somewhat schematic view of a signal generator configured tocouple to a fluid detection network.

FIG. 21 is a somewhat schematic view of an embodiment of a monitoringsubsystem.

FIG. 22 is a somewhat schematic view of another embodiment of amonitoring subsystem.

FIGS. 23–26 schematically show a possible analysis used to assess afluid distribution from a measured energy distribution.

DETAILED DESCRIPTION

FIG. 1 schematically shows a fluid detection system 10 that isconfigured to assess the distribution of a fluid. As used herein, theterm “distribution” is used to describe the absolute and/or relativepresence, quantity, and/or location of such a fluid. Fluid detectionsystem 10 includes a fluid detection network 12 and a monitoringsubsystem 14 that can be individually and collectively configured todetect a fluid distribution. The fluid detection network can beassociated with different regions that are to be tested so thatdifferent portions of the fluid detection network correspond todifferent regions of the tested area. In other words, different portionsof a fluid detection network may service different regions of a testedarea. Each region may be monitored, thus allowing the fluid distributionthroughout the tested area to be determined. A monitoring subsystem cancooperate with the fluid detection network to interpret information fromthe fluid detection network, and such information can be used to assessfluid distribution of the tested area.

Although the below disclosure describes exemplary systems that areconfigured to detect the distribution of urine in absorbent articles, itshould be understood that this disclosure is not so limited. Suchembodiments are provided for the purpose of teaching individualfeatures, functions, elements, and/or properties that may be variouslycombined while remaining within the scope of this disclosure. Detectingurine in an absorbent article is provided as only one example of thebroader application of detecting a fluid in a tested area.

Urine Detection Network

FIG. 2 schematically shows an exemplary fluid detection network 12 inthe form of a urine detection network 20. Urine detection network 20 canbe used to detect the distribution of urine in an absorbent article. Asused herein, “absorbent article” is used to describe any article thatcan hold or contain variable amounts of fluid. Although described belowin the context of a diaper, it should be understood that absorbentarticles may also take the form of bedding, garments, sanitary napkins,etc. Furthermore, absorbent articles may be configured for collectingsubstances other than fluids and fluids other than urine. In general, itis within the scope of this disclosure to test the fluid distribution ofvirtually any absorbent medium or other item that may collect a fluid. Adiaper is described as a single nonlimiting example of an absorbentarticle that may be tested.

Absorbent articles may include one or more regions, which may be testedin order to assess the degree to which each region has been wetted. Forexample, a diaper may include a front portion and a rear portion, whichmay respectively be wetted with different amounts of urine depending onwhether a user is lying in a face-up or a face-down orientation.Accordingly, urine detection network 20 may include one or moredetectors 22, which can be individually configured and positioned totest the relative or absolute urine content of such regions. In thismanner, a network of detectors can collectively test different regionsof an absorbent article to assess the location of urine throughout theabsorbent article as opposed to the mere presence of urine withoutknowledge of its distribution. Different regions may be testedindependently of one another, as groups of regions, or collectively as awhole. Furthermore, a network of detectors may indicate the remainingfunctional absorbent capacity of the article in one or more bodypositions, which in turn may be used to determine if a change can bepostponed.

The tested regions may correspond to different usage patterns, andtested wetness levels of one or more regions may be used to determinethe ability of an absorbent article to collect additional fluid withoutleaking. In some embodiments, the level of fluid in a region containingthe most fluid relative to other regions may be interpreted as the fluidlevel of the article as a whole, although other regions may be lesswetted or even unwetted. In some embodiments, the level of fluid in oneregion may be considered with respect to the wetness of other regions todetermine if the absorbent article is capable of retaining additionalfluid to adequately comply with its functional purpose. A network ofdetectors may be configured to provide information regarding the fluiddistribution of the absorbent article, i.e. the relative or absolutewetness of one or more regions of the article. Such information may beused to assess the fluid distribution of the article. Accordingly, thefluid distribution may be used to make decisions corresponding to theabsorbent article, such as whether a diaper needs changing.

A detector 22 may participate as an identifiable element within urinedetection network 20. In some embodiments, two or more detectors may beinterconnected via a bus 24. Bus 24 may include one or more seriesand/or parallel connections that operatively couple one detector toanother. In some embodiments, a detector may be inductively orcapacitively coupled to a bus. Furthermore, other network elements maybe operatively coupled to bus 24. For example, FIG. 2 shows an interfacemodule 26 coupled to bus 24. Bus 24 may be configured to effectivelylink two or more network elements, such as detectors 22 and/or interfacemodule 26. In this manner, the individual functionality of a singlenetwork element may contribute to the collective functionality of thenetwork as a whole, as is described in more detail below.

A detector 22 may be configured to test a region of an absorbent articleusing a variety of mechanisms. Detector 22 may be any element capable oftranslating the presence of urine, or another fluid or ionizedsubstance, into a detectable change in a characteristic of urinedetection network 20. As one example, a detector may change the netcapacitance of a network when the region that the detector testsexperiences a change in urine distribution. Such a change to the netcapacitance of the urine detection network may be attributed to a changein the individual capacitance of the detector resulting from thepresence of urine. Capacitance is provided as a nonlimiting example of anetwork characteristic that may be responsive to changes in urinedistribution.

A network may include a detector with characteristics that distinguishit from other detectors of the network, so that a particular detectormay be distinguished from other detectors. For example, at least onedetector may be configured with known minimum and maximum capacitancevalues, which may be different from the minimum and/or maximum values ofother detectors. Thus, a particular detector may change capacitance in amanner different from other detectors, and change the net capacitance ofall detectors differently than any other detector, or combination ofdetectors. Therefore, if the capacitance of such a detector changes,because a region associated with it becomes at least partially wetted,the change in capacitance may be attributed to a wetting of the regionserviced by that detector. Each detector may be configured with a uniquecapacitance, and the collective capacitance of all detectors, or anygroup of detectors, may be configured to signal different wetnessconditions, which depend on the region or regions of the article thathave been wetted.

In some embodiments, one or more detectors may be configured to have aknown capacitance range, while other detectors do not have preciselyidentifiable capacitance ranges, but rather a range from a set value, orrange, to a value out of a known range. Such an arrangement may beuseful to determine whether a particular region of an absorbent articleis sufficiently wetted so as to warrant a change. For example, thiscould be used to determine whether a diaper needs to be changed, withoutprecisely identifying what region of the diaper is wetted; or whether adiaper change may be avoided although an identified region is detectedas being wet.

A region serviced by an identifiable detector may be wetted, but becauseof the particular region associated with that detector, such as a regionthat is not prone to leaking, the diaper need not be changed if otherdetectors are not triggered. Nonetheless, the detector may be used todetermine the overall remaining capacity of the collection article.Other regions, which when wetted indicate that a diaper should bechanged, may be serviced by less predictable detectors that are noteasily individually identifiable, because it has been predetermined thata diaper should be changed when any region associated with such adetector becomes wetted. In such circumstances, the precise region thathas been wetted may not be indicated. The unpredicted capacitance maysignal that a change is needed because the detectors that yieldunpredicted capacitance values are positioned to service regions thatcorrespond with a need to change the diaper when at least one of thoseregions is wetted. As used herein, the term “unpredictable” is used todescribe a capacitance value outside of a predetermined range. It shouldbe understood that an “unpredictable” value is useful in identifyingwetness, because the capacitance has moved outside of a predeterminedrange. In some embodiments, the individual capacitance values of eachdetector, or groups of detectors, may be tested separately from otherdetectors, and in some embodiments the net capacitance of all detectorsis tested.

A detector 22, or a portion of the detector, may be insulated fromdirect contact and/or galvanic interaction with urine. In other words,the detector can be configured so that portions of the detector, such asmetal portions, do not physically interact with urine. The detector maybe configured so that only materials that are relatively inert withrespect to urine come into contact with urine. For example, aninsulating layer, such as plastic, selected for its lack of reactivitywith urine, may be used to shield a metal portion of a detector, whichmay undesirably react with the urine. Such a covering can prevent urine,which may be in contact with a user, from reacting with metal in a waythat could be harmful to the user. However, insulating layers can beutilized without preventing the detector from performing its desiredfunction of detecting urine.

A detector may be tuned to respond to the presence of urine if the urineexceeds a predetermined threshold amount and/or consistency. In someembodiments, such a threshold may be set to a nominal value so that anyurine will exceed the threshold. In some embodiments, the threshold maybe set to a more significant value so that an amount and/or consistencyof urine below the selected threshold will not affect the urinedetection network in the same manner as an amount and/or consistency ofurine above the selected threshold. This may be useful in avoiding falsepositive detections resulting from small amounts of moisture in thevicinity of a detector. In some embodiments, a detector may respond tothe relative amount of urine in the region serviced by the detector, andthus the detector may be used to determine the relative amount of urinein that region. In some embodiments, more than one detector may beassociated with a region, and each detector in a region may beresponsive to a different threshold of fluid.

A detector may be treated with a sensitizer to increase responsivenessto a targeted fluid. For example, a detector 22 may be treated with afluid-soluble coating configured to dissolve, or otherwise change form,when a certain degree of saturation occurs. In some embodiments, anionized substance, in a dried or other form, may be applied to thedetector. In this manner, a fluid, including an unionized fluid, and theionized substance may combine to form an ionized solution, which mayincrease detector sensitivity to some fluids and/or enable detection offluids that would not otherwise be detectable. In some embodiments, thedetectors may include a fluid collecting pad or sponge designed toretain fluid. Such pads may be treated with an ionized solution anddried, thus leaving an ionized substance on the pad. The ionizedsubstance may react with ionized and/or unionized fluids to facilitatedetection of the fluids.

A detector may include a dielectric portion configured to changedielectric properties in response to the presence of fluid. For example,in some embodiments, a detector may include opposing plates separated bya variable dielectric, such as a pad or a sponge, that changes thecapacitance of the detector in response to changes in the wetness levelof the pad. The wetness level of the pad may vary according to thedegree of wetness around the pad. The change of capacitance in a singledetector can produce a corresponding change in the net capacitance of anetwork. As described above, one or more detectors may be configured tochange the net capacitance by a different amount than one or more otherdetectors. The network may be tested to determine a wetness conditioncorresponding to the region the detector services. For example, inembodiments where capacitance is a network characteristic that changesin response to wetness, the net capacitance of the network may bemeasured or otherwise analyzed to test the network.

In some embodiments, a detector may be configured so that the distancebetween portions of the detector mechanically changes when fluid isintroduced to the detector. For example, a dielectric portion may expandand/or shrink with changing levels of wetness, thus changing thedistance between opposing plates. In some embodiments, a dielectriclayer may dissolve when exposed to a targeted fluid. In someembodiments, the dielectric layer may change dielectric properties inanother manner. In any case, such changes can be measured and/oranalyzed to assess saturation corresponding to a detector. The above areprovided as nonlimiting examples, and other detection mechanisms mayadditionally or alternatively be implemented.

FIG. 3 schematically shows a diaper 30 that includes a urine detectionnetwork 32. The urine detection network includes a bus 34 thatinterconnects detectors 36. As can be seen, the detectors are locatedproximate different regions of diaper 30. Each detector is configured totest the region corresponding to that detector's position. Urinedetection network 32 also includes an interface module 38 thatfacilitates communication with an external device. The incorporation ofurine detection network 32 into diaper 30 is provided as a nonlimitingexample of a fluid detection network servicing an absorbent article. Itshould be understood that other arrangements are contemplated.Furthermore, one skilled in the art of fluid detection may apply theabove concepts to other fluid detection systems that service other typesof tested areas. A urine detection network, or portions thereof, may bepositioned inside an outer protective layer of the diaper, or outside ofthe outer protective layer.

FIG. 4 shows a schematic cross section of an exemplary detector 50.Detector 50 includes plate 52 and plate 54, which oppose one another.The plates may be constructed from metal sheet material, or anothersuitable conductor. The plates can be respectively sealed from moistureby insulating layer 56 and insulating layer 58. The insulating layersmay be constructed from plastic or another waterproof coating material.The insulating layers may be configured to allow a plate to electricallycommunicate with a bus, which may or may not be insulated, whilepreventing undesired contact with a fluid. The insulating layers may beimplemented in virtually any form that effectively seals selectedportions of the plate from undesired fluid contact. In some embodiments,a single segment of insulating layer may effectively encapsulate aplate, and in some embodiments two or more portions of insulating layermay cooperate to collectively seal a plate. It should be understood thata sealed plate may connect to a bus.

Between plate 52 and plate 54, detector 50 includes dielectric material60. In the illustrated embodiment, dielectric material 60 includesmoisture absorbing portion 62 and a nonabsorbing portion 64. Theabsorbing portion is exposed to fluid via an opening, shown generally at66. Absorbing portion 62 is configured to change dielectric propertieswhen exposed to fluid. Therefore the capacitance of detector 50 changeswhen the detector is exposed to fluid. The change in capacitance may beanalyzed to assess the wetness condition of the region associated withthe detector. The above is only one example of a detector that may beimplemented to assess fluid distribution at a tested area. Otherconfigurations designed to respond to changes in fluid concentrationwith changes in capacitance may additionally or alternatively be used,and configurations designed to vary a characteristic other thancapacitance may be used in some embodiments.

FIG. 5 shows an exemplary urine detection network 100 configured as asheet 102, which may be incorporated into an absorbent article.Constructing urine detection network 100 as a single sheet may simplifyassembly of the absorbent article. For example, diapers may be assembledin layers by automated machines. A protective shell, absorbent core,inner fabric, and/or other portions may be layered together, cut,shaped, glued, etc. Furthermore, additional components such as elasticbands, fasteners, reinforcement supports, etc. may be used in theconstruction. Sheet 102 may be incorporated into such an assemblyprocess, so that the sheet is layered with the other portions of thediaper. In some embodiments, a pick-and-place arrangement may be used toposition a urine detection network, or portions thereof, at a desiredlocation within the diaper during assembly. Such sheet arrangements mayinclude a urine detection network assembled with a single wire, anassembly of capacitor plates, wires, and/or other components, or anyother suitable urine detection network.

Urine detection network 100 includes detectors 104 that are configuredto respond to the presence of urine by changing capacitance. A detector104 may be constructed with the same general layout as detector 50 ofFIG. 4, or other suitable arrangements may alternatively be used. Eachdetector 104 includes a first plate 106 electrically coupled to a bus108 at a first node 110 and a second plate 112 electrically coupled tothe bus at a second node 114. The plates may be effectively insulatedfrom fluid using any suitable means, including covering the plates withan insulating layer. The plates may be positioned on opposing sides of adielectric material, such as pad 116. As shown, at least a portion ofthe dielectric may be exposed so that urine may come into direct contactwith the dielectric. The dielectric may be configured with an absorbentportion that changes dielectric properties when it absorbs fluid, and orother substances. Therefore, measurement of the capacitance of the fluiddetection network may be used to assess the presence of fluid.

As shown, urine detection network 100 includes a network bus 108, towhich detectors 104 are coupled. Some detectors may be connectedimmediately adjacent the network bus, as indicated at 118, while othersmay be spaced away from the bus, as indicated at 120. FIG. 5, shows onlyone possible arrangement, and it should be understood that detectors maybe positioned to correspond to virtually any region of an absorbentarticle at which testing is desired. Furthermore, fluid detectionnetworks may be configured to service tested areas other than absorbentarticles and may be configured accordingly. One or more network bussesmay be used to facilitate placement of the various detectors thatconstitute a fluid detection network.

A fluid detection network may include an interface module configured tofacilitate interaction with a monitoring subsystem. In this manner,information corresponding to a fluid distribution tested by the networkmay be acquired and/or interpreted by the monitoring subsystem. Themonitoring subsystem may use an interface module that is complementarilyconfigured relative to an interface module of the tested fluid detectionnetwork. Some monitoring subsystems may include interface modules thatare configured to wirelessly acquire information from a fluid detectionnetwork, and/or to communicate via a direct electrical connection.Although primarily described herein with reference to wirelesslycommunicated electromagnetic energy and electrical energy communicatedvia direct electrical connection, it should be understood that fluiddetection networks may be configured to operate and/or communicate usingother energy forms, including optical energy and mechanical energy.

FIG. 5 shows an exemplary interface module in the form of a connectionnode 130. Connection node 130 includes electrical contact 132 andelectrical contact 134, which are operatively coupled to a bus 108 ofthe urine connection network. Bus 108 may be connected to a detector 104that is configured to respond to the presence of urine. One or moreinterface modules may be included in the same fluid detection network,thereby facilitating different types of interaction with a monitoringsubsystem and/or providing different areas of the tested article withwhich the monitoring subsystem may establish interaction.

A monitoring subsystem may be clipped or otherwise coupled to connectionnode 130, thus allowing the monitoring subsystem to monitor acharacteristic, such as capacitance, of the fluid detection network. Inthe illustrated embodiment, a clip 136 of a monitoring subsystem isshown in position to establish a charge path between connection node 130and the monitoring subsystem. Other arrangements are possible, and theabove is shown as a nonlimiting example. For example, in someembodiments, connection node 130 may be configured to extend out of adiaper where an electrical connection can be easily made. In general, aphysical or operative connection may be established between conductorsof a monitoring subsystem and a connection node of a fluid detectionnetwork, thus facilitating the transmission of electrical currentbetween the monitoring subsystem and the fluid detection network. Thetype of the connection and the location of the connection may vary. Themonitoring subsystem may be configured to measure characteristics of thefluid detection network, including the capacitance of the network. Insome embodiments, electrical contact 132 and electrical contact 134 mayfacilitate capacitive coupling between the network and the monitoringsubsystem.

FIG. 20 shows an exemplary interface module in the form of anenergy-converting module 150. Energy-converting module 150 may becoupled to a bus of a urine detection network. The energy-convertingmodule may be configured to collaborate with a monitoring subsystem,thus wirelessly conveying information about the urine detection networkto the monitoring subsystem. For example, a monitoring subsystem maygenerate a magnetic or electromagnetic field that energizesenergy-converting module 150. As the urine detection network changescapacitance in response to changing fluid distributions, the changingcapacitance may produce corresponding changes in the energy distributionbetween the monitoring subsystem and energy-converting module 150.Therefore, the monitoring subsystem may be used to monitor thecapacitance of the fluid detection network, which predictably changes inresponse to the fluid distribution. In this manner, the energydistribution between the monitoring subsystem and energy-convertingmodule 150 may be monitored to determine the fluid distribution.

FIG. 7 shows a schematic view of an exemplary fluid detection network160 that is made from a single layer of conductive material 162, such asaluminum foil, conductive ink, or the like. The conductive material isoriginally arranged in a generally planar configuration, and may bedisposed on a dielectric material 164. When in an initial planarconfiguration, the conductive material is not in a final desiredorientation. Folding along a fold line 166 so that a portion 168 of theconductive material is placed adjacent another portion 170 of theconductive material positions the conductive material in the desiredconfiguration. In other words, folding the conductive material completesa desired circuit. A node 172 of portion 168 can be physically connectedto a node 174 of portion 170 to form a charge path. In some embodiments,node 172 and node 174 may be capacitively coupled, or in other words,separated by a dielectric layer. Once folded, portion 168 and portion170 collectively serve as an interface module, which may interact with amonitoring subsystem. Other network elements, such as detectors, mayalso be formed from folding a single layer into two or more adjacentlayers.

Fluid detection network 160 includes detectors 176, which includeinsulated conducting plates that are positioned side by side in a planarconfiguration. In such an arrangement, ionized fluid may functionsimilar to a second opposing plate, as found in a conventionalcapacitor. For example, ionized fluid covering the plates of detectors176 may enable the plates to temporarily store charge and affect thefluid detection network's overall capacity. In other words, when ionizedfluid covers a detector of the network, the detector's capacity maychange accordingly. A layer of absorbent material may be positioned ontop of a detector to ensure complete coverage by the fluid. Furthermore,a second layer of conductive material such as aluminum foil may beplaced on top of the absorbent layer and may improve detectionresolution between dry and wet detectors. The plates of the detectorsmay be insulated from fluid by a sheet of dielectric material and/or byapplying an overcoat of dielectric material. Detectors may be configuredwith different sizes to enable distinguishing between the differentdetectors.

FIG. 8 depicts a schematic view of an exemplary fluid detection network180 that is constructed from two parallel conductors separated by adielectric layer. Portions of the dielectric layer, such as portionsassociated with detectors, may be designed to react in a predictablemanner when fluid is present. For example, a dielectric property of thatportion of the dielectric layer may change when exposed to a testedfluid. Other portions, such as portions not associated with a detector,may be kept from reacting to the fluid. To avoid reacting, such portionsmay be impregnated with a suitable compound, physically insulated,and/or otherwise protected.

The conductors and dielectric layer of fluid detection network 180 maybe arranged in a variety of configurations. For example, FIG. 9 shows across section of one possible arrangement, in which parallel conductors182 are arranged on opposite sides of a common absorbent dielectriclayer 184. The conductors are surrounded by an insulation layer 186.FIG. 10 shows another arrangement, in which conductors 188 are coveredby an insulation layer 190, which in turn is covered with a dielectriclayer 192. In these or other embodiments, the dielectric layer may beabsorbent and/or chemically reactive. The above are provided asnonlimiting examples. Other arrangements with absorbent or non-absorbentdielectric layers may be used. In some embodiments, the dielectric layermay itself provide insulation, thus rendering a separate insulationlayer unnecessary. As with other types of fluid detection networks, theoverall capacity of a dry network can be established and changes thatoccur at any detector of the network may be detected and used inassessing fluid distribution.

FIGS. 11–13 show three exemplary fluid detection network arrangementsthat include a single conductive element arranged to form one or moredetectors, a bus, and/or additional elements. In some embodiments, thesingle conductive element may take the form of a moisture-insulatedwire. Constructing the fluid detection network from a single conductiveelement may decrease the cost of the fluid detection network. Theconductive element may be shaped to form detectors at a plurality oflocations, which may be used to test the wetness at each location. Whilethe bus, detectors, and/or interface module of a fluid detection networkmay be formed from a single conductive element, it should be understoodthat insulating layers, dielectric portions, and other components mayalso be used to construct such a fluid detection network.

FIG. 11 shows fluid detection network 200, which includes bus 202,detectors 204, and an interface module 206 fashioned from a singleconductive element 208. Detectors 204 may function as simple capacitors.As described herein, capacitors may be configured to effectively measurethe wetness of a tested area by changing capacitance in response tochanges in wetness. To facilitate such measurements, materials thatchange dielectric properties in response to wetness may be utilized insome embodiments. Interface module 206 may be used to wirelesslyinteract with a monitoring subsystem, such as via mutual inductance.FIG. 12 shows a fluid detection network 210 in which a single conductiveelement 212 is shaped to form a bus 214, detectors 216, and an interfacemodule 218. Detectors 216 are formed in a coil pattern. In response towetness, a detector including a coil shaped element may changecapacitance, and/or change its own inductive behavior, which may cause ameasurable change in the overall energy absorption pattern of a fluiddetection network. FIG. 13 shows yet another exemplary fluid detectionnetwork 220 in which a single conductive element 222 is shaped to form abus 224, detectors 226, and an interface module 228. Detectors 226 areshaped as coils, and in some embodiments the detectors may be at leastpartially exposed to fluid while other elements of the network areinsulated.

A variety of methods may be used to form a fluid detection network inwhich a single conductive element is shaped to form plural networkelements, such as a bus, detectors, and/or interface module. Forexample, a wire may be bent into shape, conductive ink may be used toprint a desired pattern, conductive sheet material may be cut or etched,etc. In general, methods which minimize cost while maximizingrepeatability and speed of production are favored.

FIGS. 14–17 show an exemplary method of shaping a sheet of conductivematerial into a desired pattern, which may be used as part of a fluiddetection network. FIG. 14 shows a cross section of a portion of sheetmaterial that can be used to form a fluid detection network. The sheetmaterial includes a substrate 240, a binder 242, and a conductive layer244. The substrate may include plastic and/or another poor electricalconductor that is relatively chemically inert with respect to urine oranother tested substance. In some embodiments, the substrate may beflexible, so as to increase placement options in urine collectionarticles such as diapers. Conductive layer 244 is generally formed froma conductive sheet material suitable for establishing one or more chargepaths, through which electrical charge may move. In some embodiments,the conductive layer may include a metallic sheet material, such as analuminum foil, or another flexible conductor. Binder 242 is intermediatesubstrate 240 and conductive layer 244. As explained below, in someembodiments, the binder may be a selectively deformable layer that canbe given a desired profile. For example, binder 242 may include a hotmelt adhesive capable of adhering conductive layer 244 to substrate 240.Such a hot melt adhesive may be stamped, embossed, or otherwisephysically altered to have a desired shape. In some embodiments, asingle layer may serve as the binder and the substrate. For example, athermoplastic substrate/binder may serve as a substrate to a laminatedconductive layer, the thermoplastic substrate/binder may be heated andshaped to help establish and maintain a suitable gap distance, asdescribed below.

As shown in FIG. 15, a scorer 250 may be used to mark a pattern onconductive layer 244. In some embodiments, the scorer may take the formof a die cutting plate that is configured to physically cut through theconductive layer, and possibly a portion of the binder and/or thesubstrate. Cutting through the conductive layer effectively shapes theconductive layer into a desired conductive pattern 252. At least aportion of the binder and/or substrate may be left intact, thusproviding a stable base for the newly formed conductive pattern. Theconductive pattern may include adjacent traces, separated by a gapdistance D. After the scorer disengages the conductive layer, Gapdistance D may become very small or even closed.

As shown in FIG. 16, a cover layer 260 may be applied on the conductinglayer, or portions thereof. Cover layer 260 may be applied before orafter shaping. Cover layer 260 may be contoured to the shape of thepressed conductive layer, or the cover layer may remain substantiallyflat. Cover layer 260 may include plastic, or another suitable material,which may effectively act as an electrical insulator. Cover layer 260and substrate 240 may cooperate to seal the conductive layer, or atleast selected portions of the conductive layer. Cover layer 260 mayalso facilitate maintaining a desired gap distance D between adjacenttraces of the conductive layer.

As shown in FIG. 17, a shaper 270 may be used to further defineconductive pattern 252. In some embodiments, the shaper may take theform of a heated embossing plate. The shaper may be configured with astamping pattern 272 that complements conductive pattern 252. Thestamping pattern and the conductive pattern may be aligned, and thestamping pattern may be pressed into the conductive pattern. As shown,the conductive layer, binder, and/or cover layer may be deformed by thepressure of the shaper. In particular, the conductive layer may be givena more three-dimensional profile, which can increase a gap distance Dbetween adjacent traces of the conductive layer. An increased gapdistance may improve circuit integrity and help limit electrical shortsor other conditions that could cause a fluid detection network to behaveunpredictably.

As schematically shown in FIG. 18, a fluid detection network 280 mayinclude a data storage mechanism 282 for storing information. Forexample, a fluid detection network may include a memory that stores anidentifier that may be presented to a monitoring subsystem to facilitateidentification of the particular fluid detection network. This may beuseful, for example, if a common monitoring subsystem is used to testmore than one fluid detection network. In particular, a data storagemechanism may include information regarding the type, size, and/orcapacity of an absorbent article that the interface module is associatedwith, thereby allowing customized quantitative measurements to beperformed.

To facilitate a wireless exchange of information between a monitoringsubsystem and the fluid detection network, one or more energy-convertingmodules may be operatively coupled to the fluid detection network. Anenergy-converting module may facilitate the exchange of energy betweenthe fluid detection network and a monitoring subsystem. The exchange ofenergy may be measured and/or analyzed by the monitoring subsystem. Acharacteristic of the fluid detection network may correspond to theenergy exchange between the fluid detection network and the monitoringsubsystem. In particular, one or more of the fluid detection network'scharacteristics, such as capacitance, may be determined based on themonitored energy exchange.

In some embodiments, an energy-converting module includes a coil coupledto a fluid detection network bus. The coil may be configured to convertenergy generated by an inducer into electromotive force within the fluiddetection network. An energy distribution between the fluid detectionnetwork and the inducer may be measurably influenced according to thecapacitance, or other characteristic, of the fluid detection network.Therefore, measurement and analysis of the energy distribution patternmay be used to detect the distribution of urine.

Monitoring Subsystem

FIG. 19 schematically shows an exemplary monitoring subsystem 300. Amonitoring subsystem may take the form of a portable device, which maybe moved from one testing location to another. In some embodiments, amonitoring subsystem may include a combination of stationary andportable componentry, which may be constructed as two or more separatedevices. A monitoring subsystem may be configured for measuring and/oranalyzing fluid distribution independent of other devices, or amonitoring subsystem may be configured to cooperate with one or moreother devices to measure and/or analyze fluid distribution. A monitoringsubsystem may be adapted to present information to other devices foranalysis and/or notification via wired or wireless transmission modes.In some embodiments, the monitoring subsystem may send or receive datathat may be interpreted or further analyzed to determine a fluiddistribution. Furthermore, elements of the monitoring subsystem maytransmit raw and/or analyzed data to other elements of the monitoringsubsystem or to another device via wired or wireless communication. Suchdata may be further analyzed, recorded, validated, reported, etc. Forthe purpose of simplicity, this disclosure primarily focuses on amonitoring subsystem that is configured as a unitary portable device.However, monitoring subsystems constructed of two or more devices arealso within the scope of this disclosure. Furthermore, while describedin the context of measuring and analyzing a fluid distribution, itshould be understood that detection networks may be configured fordifferent types of measurements, and monitoring subsystems may be usedto wirelessly assess information obtained from such measurements.

Monitoring subsystem 300 includes an analyzing module 302. As indicatedin dashed lines, monitoring subsystem 300 may also include an interfacemodule 304, an inducer module 306, a sampling module 308, and/or anotification module 310. Analyzing module 302 may be configured toanalyze information in order to assess the fluid distribution of atested area serviced by a fluid detection network. Analyzing module 302may include hardware, firmware, and/or software used to performmeasurements and/or analysis. As nonlimiting examples, an analyzingmodule may take the form of a circuit board designed for the specificpurpose of analyzing a fluid detection network, or an analyzing modulemay take the form of a general computer capable of running softwaredesigned to analyze a fluid detection network. In a simple embodiment,the analyzing module may include componentry for directly measuring thecapacitance of a fluid detection network. In some embodiments, theanalyzing module may be configured to perform data analysis, asdescribed in more detail below.

A monitoring subsystem and a fluid detection network may becommunicatively coupled by an information link. The information link maybe a wired or wireless connection. In some embodiments, the analyzingmodule may acquire information for analysis via an interface module 304that is physically coupled to a connection node of a fluid detectionnetwork. In some embodiments, the analyzing module may wirelesslyacquire information for analysis. Information may be wirelessly acquiredvia an inducer module 306 and/or a sampling module 308. In either case,acquired information may be delivered to the analyzing module via adirect connection, such as an electrical or optical connection, or theinformation may be wirelessly transmitted, such as via a radio signal.

When present, an interface module 304 may electrically couple to aconnection node of a fluid detection network, thus electrically linkingthe connection node of the fluid detection network to analyzing module302. In this manner, analyzing module 302 can read the net capacitance(or other characteristic) of the urine detection network via a directphysical connection. FIG. 5 shows an example of a connection node towhich interface module 304 may connect. As mentioned above, connectionnodes may be placed for easy access, so that fluid distributionmeasurements may be easily taken. Though schematically shown as a simpleclip arrangement, it should be understood that a more robust interfacemay be utilized for coupling a fluid detection network to a monitoringsubsystem.

In some embodiments, an interface module in the form of a wirelesssignal generator may be directly coupled to a fluid detection network.For example, as shown in FIG. 20, a self-powered signal generator 312may be coupled to a bus of a urine detection network via a connectionnode 314. Signal generator 312 may be configured to produce a signalthat may be received and/or analyzed by a monitoring subsystem. In theillustrated embodiment, signal generator 312 is directly coupled to thenetwork and configured to predictably change aspects of the producedsignal (frequency, modulation, duty cycle, etc.) in response to changesin the capacitance of the network. In other words, urine distributionaround the corresponding urine detection network controls thecapacitance of the urine detection network, and the capacitance of theurine detection network controls at least one aspect of a signalproduced by signal generator 312. Analyzing module 302 may be configuredto receive the broadcast signal and determine the capacitance of thenetwork. In this manner, the urine distribution of a tested area can beassessed.

Signal generator 312 may include an internal or external antenna 316configured to facilitate signal transmission. The signal generator mayalso include a battery, or other power source, used to power signalproduction, and/or the signal generator may utilize power delivered viatransmitted electromagnetic energy to generate a signal fortransmission. In some embodiments, other configurations of signalgenerators may be employed for transmitting raw and/or analyzed data.

In some embodiments, a direct reading of capacitance, or another networkcharacteristic, is not taken. Instead, a fluid detection network'sresponse to an induced magnetic or electromagnetic field may be sampledby a monitoring subsystem. The fluid detection network's response may besampled without directly contacting the fluid detection network, or atleast without establishing a direct charge path between the monitoringsubsystem and the fluid detection network. Therefore, this type ofsampling is referred to as “wireless.” The wirelessly sampledinformation may be used to assess fluid distribution of a tested areaserviced by a fluid detection network.

Monitoring subsystem 300 may include an inducer module 306 configured towirelessly interact with a fluid detection network. Inducer module 306may be configured to generate a desired energy field. As a nonlimitingexample, inducer module 306 may include a signal generator, such as aradio frequency oscillator, operatively coupled to a coil. The signalgenerator may drive an electrical signal in either transient orcontinuous form through the coil to produce a desired energy field. Thesignal generator may include a voltage-controlled oscillator,phase-lock-loop based synthesizer, direct digital synthesizer, etc. Thesignal generator may be configured to selectively adjust the waveform,frequency, or duty cycle of the driven signal to produce the desiredenergy field.

As mentioned above, a monitoring subsystem may be configured to assess afluid distribution of an area serviced by a fluid detection network,without establishing a physical connection between the fluid detectionnetwork and the monitoring subsystem. In such cases, a fluid detectionnetwork may be configured to absorb and/or reflect emitted energy in adistinctly different manner according to the fluid distribution of thetested area. The monitoring subsystem may emit an energy field andmeasure the energy distribution between the monitoring subsystem and thefluid detection network to determine the fluid distribution. Forexample, at least one characteristic of a network, such as capacitance,impedance, or resonance frequency, may affect a pattern of absorbedenergy by the network and/or backscattered energy reflected from thenetwork. Such characteristic may be indicative of a fluid distribution.Therefore, the characteristic may be determined to assess the fluiddistribution.

An energy distribution function may be constructed from two or moremeasurements. For example, changes in an induced energy field may beperiodically measured as the frequency of an induced field is changed.Such measurements may be taken at an analyzing module, a samplingmodule, or another component of the monitoring subsystem. Thousands ormore of such measurements may be taken every second. The results of themeasurements may be compiled to form an energy distribution function,which may be graphically represented as a curve. The energy distributionfunction may be analyzed to determine the state of the correspondingfluid detection network. For example, one or more parameters of theenergy distribution function may be compared to a set of storedparameters corresponding to known fluid detection network states. Ananalyzing module may be used to construct and/or analyze the energydistribution function.

Analysis of an energy distribution function, as opposed to a singlemeasurement, may facilitate identifying the state of a fluid detectionnetwork. An energy distribution function, which may include measurementstaken at several frequencies over a short period of time, may also beused to compensate for variables that make single measurements lessaccurate. The pattern of energy exchange may be influenced by variablesother than the capacitance of the fluid detection network. For example,a magnetic coupling coefficient K may change according to the proximityand orientation of an inducer and a fluid detection network affectingenergy distribution. Analysis of an energy distribution function may beused to identify characteristics of a fluid detection network, such ascapacitance, even if the K value changes. Analysis of an energydistribution function may additionally or alternatively compensate forother variables.

As is schematically shown in FIG. 19, monitoring subsystem 300 mayinclude a notification module 310. Notification module 310 may beconfigured to provide audio, visual, and/or mechanical information thatcorresponds to the fluid distribution of an area serviced by a fluiddetection network. For example, if a tested area is wetted, notificationmodule 310 may turn on a light that indicates the wetted state of thetested area. In some embodiments, the notification module may sound anaudible alert, mechanically vibrate, or otherwise generate an indicationof a fluid distribution. In some embodiments, the notification modulemay be configured to provide information corresponding to the individualdetectors of a fluid detection network. An amount of information and theresolution of the information presented by a notification module may beselected according to a desired use and the capabilities of the fluiddetection network. When present, a notification module may be physicallyconnected to other components of the monitoring subsystem, or thenotification module may be a stand-alone unit.

As mentioned above, a fluid detection network may be configured forwireless interaction with a monitoring subsystem. In particular, whenexposed to an induced energy field, an energy distribution patternbetween a monitoring subsystem and a fluid detection network may beindicative of the fluid distribution of the area serviced by the fluiddetection network. Due to the dynamic nature of such a fluid detectionnetwork, changes that are caused by the presence of fluid, such as achange in an inductance to capacitance ratio, may cause variations incharacteristics of a network, such as impedance, the measure of thevoltage and current step-up at resonant frequency, or others. Inaddition, background noise, changes in temperature, and/or changes inthe shape, position, and/or orientation of a fluid detection network mayintroduce additional test variables. A sampling module 308 may beconfigured to facilitate data analysis that may be used to reducedependency on computation of K and/or other test variables. The use of asampling module may also allow the manufacturing tolerances of the fluiddetection network to be more relaxed, resulting in a less expensivetesting system.

A sampling module 308 may be positioned within the energy fieldgenerated by inducer module 306. The sampling module may include a coil,amplifying circuitry, and/or other componentry configured to measure theinduced energy field. The induced energy field may be influenced byexternal factors, such as a fluid detection network that is at leastpartially absorbing and/or reflecting energy from the induced energyfield. During testing, a sampling module may be positioned within anoperating distance of an energy-converting module of a fluid detectionnetwork. The sampling module and the energy-converting module may affecteach other's response to the induced field. Furthermore, a change in thefluid distribution of the area serviced by the fluid detection networkmay cause a corresponding change in the energy distribution patternbetween the inducer, the fluid detection network, and the samplingmodule. Such changes in the energy distribution pattern may be used toassess the fluid distribution of an area serviced by the fluid detectionnetwork.

As indicated in FIG. 21, a monitoring subsystem 320 may include asampling module 322 that is physically connected to an analyzing module324 and an inducer module 326. In this manner, the relative orientationand position of the inducer module and the sampling module are fixed.Therefore, the sampling module and the inducer module move together andmay be positioned within an operating distance of a fluid detectionnetwork 328 when testing the network. A monitoring subsystem may beconfigured so that the sampling module is positioned in a certainorientation during testing, such as between the inducer module and thefluid detection network. Such a relationship may allow the samplingmodule to at least partially mirror changes in the corresponding fluiddetection network, provide a fixed reference for computation ofvariables, and/or reduce dependency on accurate computation of K, as isdescribed in more detail below.

As indicated in FIG. 22, a monitoring subsystem 330 may include asampling module 332 that is a physically independent unit, which is notphysically fixed to an inducer module 334. In some embodiments, such asampling module may be positioned in a substantially fixed relationshiprelative to a fluid detection network 336. The sampling module may bepositioned immediately proximate the fluid detection network, or thesampling module may be separated from the fluid detection network, suchas by one or more layers of clothing. For example, the sampling modulemay be configured for placement in a user's pocket or for directattachment to an absorbent article.

The network's energy absorption may be influenced by the presence offluid and therefore the combined energy absorbent pattern of thesampling module and the network's energy-converting module may beindicative of a network's state. The advantage of such a configurationis that while the network's circuitry is kept at a minimum, the samplingmodule may include componentry that modifies the energy exchange patternto include information that yields computation of K or other testvariables unnecessary. In addition, the sampling module and themonitoring subsystem may be configured so that their relative positionat the time of testing may be identified without affecting a network'sresponse. A sampling module may be at least partially self-powered.

FIG. 23 shows a reference curve 400 (energy distribution function) thatrepresents an energy distribution at a monitoring subsystem. Such amonitoring subsystem may include an inducer configured to generate asignal with known parameters, such as frequency, amplitude, modulation,etc. In particular, the inducer can generate a signal that steps througha range of frequencies, as indicated by the frequency steps comprisingthe horizontal axis of the illustrated plot. The monitoring subsystemmay also include a sampling module at which one or more characteristicsof the generated signal may be measured. The measured characteristic maybe represented as a quantitative level, as indicated by the verticalaxis of the illustrated plot.

The sampling module and the inducer may be positioned in a fixedrelationship relative to one another. Fixing the relative position ofthe sampling module and the inducer may help reduce the number ofvariables that influence energy exchange between the elements. As anexample, a fixed relationship may establish a substantially constant Kvalue between the inducer and the sampling module. Although describedwith reference to a monitoring subsystem that includes an inducerconfigured to exchange energy with a sampling module, it should beunderstood that the disclosed analysis may be used with otherarrangements that effectuate a measurable exchange of energy with afluid detection network.

Reference curve 400 is indicative of a series of measurements taken atthe sampling module in a controlled environment, in which externalfactors are not influencing energy exchange between the sampling moduleand the inducer. Such a curve may be used as a baseline to which testcurves may be compared. In particular, reference curve 400 may be usedas a reference to analyze test curves measured when energy exchangebetween the sampling module and the inducer is influenced by externalfactors, such as the presence of a fluid detection network.

A fluid detection network may measurably influence energy exchangebetween an inducer and a sampling module. As the capacitance of thefluid detection network changes in response to a changing fluiddistribution, the fluid detection network may cause a correspondingchange in the energy exchange between the inducer and the samplingmodule. The change may be dependent on the relative orientation of theinducer and the sampling module to the urine detection network. Analysisof an energy distribution function may be used to interpret the measuredchange in the capacitance of the fluid detection network. Such analysismay be made even if the position of the inducer and the sampling modulerelative to the urine detection network changes within an acceptablerange. In other words, changes in the K value can be compensated for bythe disclosed analysis. For example, the angle of a test curve relativeto a reference curve at the point where the curves intersect mayindicate the K value. If the K value is within an acceptable range, theresults from the analysis may be reported. If the K value falls out ofan acceptable range, additional measurements may be taken and/or a usermay be notified to adjust the position of a monitoring subsystem.

FIG. 24 shows reference curve 400, as well as test curve 402 and testcurve 404. Test curve 402 and test curve 404 correspond to a testingsituation in which a fluid detection network is queried by a monitoringsubsystem positioned so that the sampling module is placed between theinducer and the energy-converting module of a fluid detection network.The test results are influenced by a fluid detection network in a drystate, and thus, each test curve is different from reference curve 400.In other words, the fluid detection network has a capacitance thatreflects its dry condition, and the capacitance can be detected by acorresponding change in the energy exchange relative to a situation inwhich the urine detection network does not influence the energyexchange.

Test curve 402 and test curve 404 correspond to measurements taken whenthe monitoring subsystem is in two different orientations relative tothe fluid detection network. Such differences in orientation arereflected in the differences between the test curves relative to oneanother. However, despite the differences in the test curves, analysisof the curves can provide information corresponding to the state of thetested fluid detection network.

As can be seen in FIG. 24, test curve 402 and test curve 404 intersecteach other at an intersection point 406 and an intersection point 408.Reference curve 400 also passes through intersection point 406 andintersection point 408, or at least within an acceptable range of thosepoints. In other words, both test curves and the reference curve havecommon intersection points corresponding to a frequency or range offrequencies of the signal generated by the inducer. In the illustratedplot, a dry urine detection network corresponds to intersection pointsoccurring approximately around a frequency step of 11 and a frequencystep of 21. Such frequency steps correspond to frequency values, whichmay be tuned to provide a meaningful reference curve in which energyexchange can be measured. Such results for a dry fluid detection networkmay be predetermined under known conditions and used as a comparisonwhen testing urine detection networks. For example, a query that yieldsan intersection point of a test curve compared to a reference curve, ora different test curve, within an acceptable range of predeterminedintersection point 406 and/or intersection point 408 may be interpretedas resulting from a urine detection network in a dry condition. This maybe true for a range of K values that may be determined by analyzing atest curve, such as by comparing the angle of the test curve relative tothe reference curve at the intersection point.

FIG. 25 shows test curve 410 and test curve 412 with reference curve400. Similar to FIG. 24, the test curves and the reference curvesintersect at a common point, or region, as shown at 414 and 416.Intersection points 414 and 416 correspond to a urine detection networkin which a first detector is positively testing for urine, and thus ischanging the net capacitance of the fluid detection network. The changein capacitance is reflected in the shift of intersection points 414 and416 when compared to intersection points 406 and 408. The location ofthe intersection points may be interpreted as resulting from a urinedetection network in which the first detector is signaling a fluiddistribution in which a region serviced by the first detector is wet.

FIG. 26 shows another scenario in which a urine detection network issignaling a wet condition different from that shown in FIG. 25. In otherwords, a second detector is signaling a wet condition. Therefore, thenet capacitance of the urine detection network is different, which isreflected by test curves 420 and 422. As shown, intersection points 424and 426 are shifted from intersection points 414 and 416 of FIG. 25 andintersection points 406 and 408 of FIG. 24. The location of intersectionpoints 424 and 426 may be interpreted as resulting from a urinedetection network in which the second detector is signaling a fluiddistribution in which a region serviced by the second detector is wet.

Test curves may be compared to reference curves or to other test curvesto identify intersection points, or other relationships that may be usedto assess fluid distribution. As explained above, the intersectionpoints are at least partially resistant to variations in K. Therefore,intersection points may be used to identify capacitance values of aurine detection network. Each possible network state may bepredetermined under controlled conditions so that such comparisons maybe made (first detector wet, second detector wet, first and seconddetector wet, etc.) As mentioned above, the network may be configured sothat each possible network state has a unique net capacitance. As can beappreciated, changes in the capacitance of a urine detection networkcause a corresponding measurable change in energy distribution. Suchchanges may be analyzed by comparing tested responses with knownresponses that have been predetermined. In this manner, analysis may beused to determine the state of a urine detection network. Because theanalysis can be performed with differing K values, which correspond todifferent monitoring subsystem positions and/or orientations,flexibility in testing scenarios is achieved.

In some embodiments, aspects of a test curve, and/or reference curve,other than an intersection point may be analyzed. For example, testcurves typically experience a deviation, such as deviation 430 anddeviation 432 of FIG. 27. Such deviations may be analyzed to determinethe capacitance of a measured urine detection network. Analysis mayinclude position of inflection points bounding a deviation, distancebetween inflection points bounding a deviation, and/or angle ofdeviation. Other criteria for analyzing test curves are contemplated. Inparticular, other comparisons between test curves and a reference curvemay be used to interpret the capacitance of a urine detection network.

Furthermore, two or more energy distribution functions, such as energydistribution functions constructed from sets of measurements taken atdifferent times, may be compared to one another. Comparisons between twoor more energy distribution functions may be used to assess informationabout the state of a fluid detection network and/or to verify testresults.

Background noise, or interference, may affect the results of one or moretest measurements. To accurately detect the state of a network, theeffects of interference on a test curve may need to be identified andcompensated for. The use of a sampling module that yields a referencecurve may provide the ability to detect interference. For example, atest curve that is substantially different from the reference curve,while the sampling module is positioned away from the influence of anetwork, may provide an indication of interference. Analyzing such testcurves may provide information about the interference pattern and may beused to exclude the effects of interference from further measurements.In addition, numerical and statistical filters may be applied to detectadverse effects of a transient interference and/or a fluctuatinginterference. As used herein, background noise and interference includesanything besides a tested fluid detection network that is affectingmeasurements taken by a monitoring subsystem. In other words, anysignal, information, energy field, etc. received outside of aninformation link established between a monitoring subsystem and a fluiddetection network may be referred to as background noise and/orinterference.

In some embodiments, more than one sampling module may be used in takingdifferential measurements that may overcome the adverse effects ofbackground noise on measurements. For example, two sampling modules maybe fixed on opposite sides of an inducer module at substantially equaldistances from the inducer module. Measurements of induced signals atboth locations will result in two test curves. When no network ispresent, the test curves should be substantially similar, even in anoisy environment, as both will respond similarly to the noise. When anetwork is present, both modules will respond according to therespective distance and orientation of the sampling module relative tothe network and the inducer. The difference between the two test curvesmay be attributed to the position of the sampling modules relative tothe fluid detection network and/or the state of the fluid detectionnetwork.

Although the present disclosure has been provided with reference to theforegoing operational principles and embodiments, it will be apparent tothose skilled in the art that various changes in form and detail may bemade without departing from the spirit and scope defined in the appendedclaims. The present disclosure is intended to embrace all suchalternatives, modifications and variances. Where the disclosure orclaims recite “a,” “a first,” or “another” element, or the equivalentthereof, they should be interpreted to include one or more suchelements, neither requiring nor excluding two or more such elements.

1. A urine detection network, comprising: a first detector configured toservice a first region of a urine collection article; at least a seconddetector configured to service a second region of the urine collectionarticle; and a conductive element that electrically couples the firstdetector to the second detector; wherein the first detector and thesecond detector are collectively configured to indicate a fluiddistribution of the urine collection article; wherein the firstdetector, the second detector, and the conductive element areconstituent elements of a single conductive element; and wherein foldinga portion of the single conductive element creates an LC circuit.
 2. Theurine detection network of claim 1, wherein the urine detection networkhas a net capacitance derived from at least a first capacitance of thefirst detector and a second capacitance of the second detector, andwherein the net capacitance of the urine detection network indicatesfluid distribution of the urine collection article.
 3. The urinedetection network of claim 2, wherein the first capacitance rangesbetween a predetermined minimum and a predetermined maximum.
 4. Theurine detection network of claim 2, wherein the first capacitance rangesbetween a predetermined minimum and a value outside of a predeterminedrange.
 5. The urine detection network of claim 2, wherein the firstcapacitance ranges between a predetermined maximum and a value outsideof a predetermined range.
 6. The urine detection network of claim 1,wherein the urine detection network has a net inductance derived from atleast a first inductance of the first detector and a second inductanceof the second detector, and wherein the net inductance of the urinedetection network indicates fluid distribution of the urine collectionarticle.
 7. The urine detection network of claim 6, wherein the firstdetector includes a coil shaped conducive element.
 8. The urinedetection network of claim 1, wherein a characteristic of the firstdetector measurably changes to a first value in response to a firstthreshold of urine wetting the first region of the urine collectionarticle, and wherein a characteristic of the second detector measurablychanges to a second value in response to a second threshold of urinewetting the second region of the urine collection article.
 9. The urinedetection network of claim 8, wherein the first value is different thanthe second value.
 10. The urine detection network of claim 9, whereinthe first value is a first capacitance and the second value is a secondcapacitance.
 11. The urine detection network of claim 8, wherein thefirst threshold and the second threshold are substantially equal. 12.The urine detection network of claim 8, wherein the first threshold isdifferent than the second threshold.
 13. The urine detection network ofclaim 8, wherein the first threshold is a nominal amount of urine. 14.The urine detection network of claim 8, wherein the first threshold ismore than a nominal amount of urine.
 15. The urine detection network ofclaim 8, wherein the characteristic of the first detector includes acapacitance of the first detector, and wherein the characteristic of thesecond detector includes a capacitance of the second detector.
 16. Theurine detection network of claim 15, wherein a dielectric property ofthe first detector measurably changes in response to a first thresholdof urine wetting the first region of the urine collection article, andwherein a dielectric property of the second detector measurably changesin response to a second threshold of urine wetting the second region ofthe urine collection article.
 17. The urine detection network of claim1, wherein the first detector includes a sensitizer.
 18. The urinedetection network of claim 17, wherein the sensitizer includes a dryionized substance.
 19. The urine detection network of claim 1, furthercomprising an interface module in electrical communication with thefirst detector and the second detector.
 20. The urine detection networkof claim 19, wherein the interface module includes an energy convertingmodule configured to predictably wirelessly interact with a monitoringsubsystem based on the fluid distribution of the urine collectionarticle.
 21. The urine detection network of claim 19, wherein theinterface module includes a connection node from which a characteristicof the urine detection network can be directly measured.
 22. The urinedetection network of claim 21, wherein a net capacitance of the urinedetection network can be directly measured at the connection node. 23.The urine detection network of claim 21, wherein a net inductance of thenetwork can be directly measured at the connection node.
 24. The urinedetection network of claim 21, wherein the interface module isconfigured for capacitive coupling with a monitoring subsystem.
 25. Theurine detection network of claim 1, wherein an energy exchange patternof the urine detection network corresponds to the fluid distribution ofthe urine collection article.
 26. The urine detection network of claim1, wherein the first detector and the second detector aredistinguishable.
 27. The urine detection network of claim 26, whereinthe first detector has a first capacitance when the first region iswetted, and wherein the second detector has a second capacitance,different than the first capacitance, when the second region is wetted.28. The urine detection network of claim 1, further comprising aflexible substrate on which the first detector and second detector arearranged.
 29. The urine detection network of claim 28, wherein thesubstrate is configured for incorporation into a diaper.
 30. The urinedetection network of claim 1, wherein the single conductive element isformed from a generally planar sheet material.
 31. The urine detectionnetwork of claim 1, wherein the first detector and the second detectorare formed by shaping a wire.
 32. The urine detection network of claim1, wherein the first detector and the second detector are formed byshaping two conductive wires that are separated by dielectric material.33. The urine detection network of claim 1, wherein a gap betweenconductive elements of the urine detection network is shaped by applyingpressure on a binder layer.